Self-priming conversion unit for centrifugal pump systems



Aug. 7, 1956 v. 'JACUZZl 2,757,681 SELF PRIMING CONVERSION UNIT FOR CENTRIFUGAL PUMP SYSTEMS Filed Oct. 2, 1953 IN VEN TOR.

VALE/PIANO JAGUZZ/ BY HIS AT T ORA/E78 United States Patent 'Ofiiice 2,757,681 Patented Aug. 7, 1956 SELF-PRHVHNG CONVERSION UNIT FOR CENTRIFUGAL PUMP SYSTEMS Valeriano Jacuzzi, Oakley, Calif., assignor to .lacuzzi Bros, Incorporated, a corporation of California Application October 2, 1953, Serial No. 383,904

6 Claims. (Cl. 137-112) My invention relates to centrifugal pump systems and more particularly to a self-priming conversion unit for conventional centrifugal pump systems, and self-priming centrifugal pump systems involving such conversion unit.

Centrifugal pumps, while possessed of many advantages over other types of pumps, are known for their'inability to pump air, and consequently, if a conventional type centrifugal pump system should lose prime, the system loses its ability to pump water until steps are taken to reprime the system.

Among the objects of the present invention are:

1. To provide a novel and improved means for converting a conventional centrifugal pump system to a selfpriming system;

2. To provide a novel and improved means for converting a conventional centrifugal pump system to a selfpriming system and at the same time permit of the elimination of any existing foot valve;

3. To provide a novel and improved means for converting a conventional centrifugal pump system to a selfpriming system which conversion unit will permit of maximum efiiciency in the functioning of the centrifugal pump;

4. To provide a novel and improved conversion unit for converting a conventional centrifugal pump system to a self-priming system, which will result in a self-priming system in which the self-priming feature requires no springs;

5 To provide a novel and improved self-priming system; and

6. To provide a novel and improved self-priming system employing a centrifugal pump.

Additional objects of my invention Will be brought out in the following description of a preferred embodiment of the same taken in conjunction with the accompanying drawings wherein Figure 1 is a schematic view of a conventional centrifugal pump system converted to a self-priming pump system embodying the present invention;

Figure 2 is a view in section through the conversion unit incorporated in the system of Figure 1.

In referring to the conventional type centrifugal pump systems, I am generally concerned with any centrifugal pump system having a suction line extending down below the pump into a well or other source of liquid to be pumped, and in which system no provision exists for selfpriming the pump in the event the pump should lose prime.

Referring to the drawings for details of my invention in its preferred form, the invention, for illustrative purposes, has been shown applied to a centrifugal pump system of simplest form, involving a centrifugal pump 1 having a discharge connection 3, and an inlet connection 5 to which is coupleda suction line 7. Interposed in the suction line, preferably in proximity to the pump, is the conversion unit 9 of the present invention, to which is connected a priming chamber 11 by means of a priming connection 13 which threadedly connects in the wall of the unit. Into this priming chamber, the pump discharges through a connecting pipe 15.

The conversion unit 9 comprises a casing 17, preferably cylindrical in form and of a diameter corresponding to that of the suction line, this casing having open ends and defining a flow passage longitudinally therethrough.

Means is provided for introducing water into this passage through the wall of the casing, such means including a priming connection extension 19 leading into the casing from the point of attachment of the priming connection 13, and terminating therein in a discharge end 21 directed substantially along the longitudinal axis of the casing. The extension defines a passage forming a continuation of the priming connection.

The discharge end of the extension is preferably of Venturi shape and bounded by a primary valve seat 23, internally thereof. This primary valve seat constitutes an element of a normally-open valve assembly 25 for closing off the extension at its discharge end, the other component of the assembly being a valve 27 adapted to fit the seat and having a valve stem 29 extending therefrom. This valve is slidably supported along the longitudinal axis of the casing in line with the valve seat 25 by a hollow substantially cylindrical guide 31 threadedly mounted in the wall of the extension and terminating at one end in a secondary valve seat 33 in parallel spaced relationship to the primary valve seat 23. In a quiescent state, the valve normally engages the secondary valve seat, with the valve stem slidably passing therethrough into the hollow guide, and in such quiescent state, the valve is normally restrained from movement towards the primary valve seat. This restraint is accomplished by means including a flange 35 about the valve stem in spaced relationship to the valve, and a pair of releasable locking pawls 37, 39 which are swingably mounted at diametrically opposite points in the wall of the valve guide, each in its respective slot 41 formed in the wall of such guide. These pawls are each weighted on its outer side so as to cause it to swing inwardly into locking engagement with the flange. These pawls are adapted to be actuated out of such locking engagement by the action of a check valve 43 disposed immediately there below.

Such check Valve constitutes an element of a check valve assembly 45 involving in addition to the valve 43, a valve seat 47 spanning the proximate end of the casing, being preferably formed as part of a coupling element 49 which is threadedly secured in such end of the casing and itself is recessed and threaded in its exposed end 50 to permit of the coupling thereto of a section of the suction line pipe. The check valve associated with such valve seat, carries a skirt 51 depending therefrom through the valve seat and functioning as a seating guide, while on its upper side, it is provided with a pawl actuating element in the form of an upwardly extending neck 53 terminating in a head 55 within the valve guide and in proximity to the pawls. The lower ends 57 of the pawls are sloped such as to cause the actuating element of the check valve to exert an outward component of force against each pawl when engaging the same, the head of such actuating element being preferably concaved on its upper side and provided with perforations 59 to facilitate escape of any sand that might have collected in the guide.

In the closed position of the priming valve 27, precautions are taken to avoid possibility of leakage through the valve seat 33. This is accomplished by a sealing ring 61 of rubber or the like about the valve stem 29, at a point which will cause it to engage the underside of the valve seat when the priming valve 27 seats against the primary valve seat.

In utilizing the conversion unit to change over a con ventional type centrifugal pump system to a self-priming system, the conversion unit is interposed in the suction 3 line of the system and connected to a priming chamber, all as depicted in Figure l of the drawings. Inasmuch as the check valve assembly will perform the function previously attributed to a foot valve, the foot valve existing in the system to be converted, may be removed if desired at the time of installing the conversion unit.

It will be apparent, that when the conversion unit is installed in the manner indicated, that the water from the priming chamber will flood the system down to the check valve assembly. Upon starting the centrifugal pump, water will be circulated through the priming circuit which includes the priming chamber and the conversion unit, and by making the flow capacity through the priming connection 13 and conversion unit less than that of the capacity of the centrifugal pump, a sub-atmospheric pressure will be developed within the conversion unit sutficient to lift the check valve off its seat.

At this stage in the operation of the self-priming feature, the suction line may have considerable air below the check valve, and consequently the initial lifting of the check valve will permit escape of this air which will mix with the water in the priming circuit and be drawn through the centrifugal pump to be discharged into the priming chamber, where the air will escape to the surface.

Ultimately, the water in the well will fill the suction line to the check valve and combine with the water in the conversion unit to form a solid column of water to the centrifugal pump.

During the period, however, when the air is being drawn out of the suction line, the lifting force against the check valve will be materially less than when a solid column of water exists, and advantage is taken of this phenomenon to preclude unlocking of the priming circuit valve during the period of air removal in the operation of the system, by so adjusting the distance between the actuating element and the locking pawls as to preclude engagement of the pawls while the air is being withdrawn, and yet permit such engagement when a solid column of water is created. Accordingly, when this latter event occurs, the system is fully primed, and the resulting spreading of the pawls will unlock the priming circuit valve and permit the same to rise and seat against the primary valve seat and thus close off the priming circuit.

When the system shuts down, the pressures will equalize throughout the priming circuit, the check valve will seat, the priming circuit valve will drop to the secondary valve seat and be again locked by the pawls against upward movement.

Should the pump system, prior to conversion, already include an open tank or a pressure tank, the open tank or pressure tank may be utilized in the capacity of the priming chamber previously considered.

It will be apparent from the foregoing, that the conversion unit of the present invention makes it readily and conveniently possible to convert a conventional type centrifugal pump system to a self'priming system with all the advantages arising therefrom as previously outlined. Accordingly, while I have disclosed my invention in its preferred form, and in considerable detail, the same is subject to alteration and modification without departing from the underlying principles involved, and I accordingly do not desire to be limited in my protection to such specific details except as may be necessitated by the appended claims.

I claim:

1. A conversion unit for converting a conventional type centrifugal pump system to a self-priming system, comprising a casing having open ends and defining a flow passage, means for introducing flow of water into said passage, said means including a priming connection extension leading into said casing and terminating in a discharge end, normally-open valve means including a valve adapted for closing off said extension, means normally restraining said valve against closing off said primltl 4 ing connection extension, and means responsive to liquid flow to the exclusion of gas flow, for releasing and urging said valve to its closing off position.

2. A conversion unit for converting a conventional type centrifugal pump system to a self-priming system, comprising a casing having open ends and defining a flow passage, means for introducing flow of water into said passage, said means including a priming connection extension leading into said casing through a wall thereof and having a discharge end directed substantially along the longitudinal axis of said casing, normally-open valve means adapted for closing off said extension, said normally-open valve means involving a primary valve seat bounding the discharge end of said extension and a valve adapted to fit said seat and having a valve stem extending therefrom, means slidably supporting said valve and valve stem along the longitudinal axis of said casing in line with said valve seat, said means including a hollow substantially cylindrical guide mounted in the wall of said extension and terminating at one end in a secondary valve seat in parallel spaced relationship to said primary valve seat, said valve abutting said secondary valve seat with its stem slidably passing therethrough into said hollow guide, means normally restraining said valve against movement toward said primary valve seat, and means responsive to liquid flow to the exclusion of gas flow for releasing and urging said valve to seating position against said primary valve seat.

3. A conversion unit for converting a conventional type centrifugal pump system to a self-priming system, comprising a casing having open ends and defining a flow passage, means for introducing flow of water into said passage, said means including a priming connection extension leading into said casing through a wall thereof and having a discharge end directed substantially along the longitudinal axis of said casing, normally-open valve means adapted for closing off said extension, said notmally'open valve means involving a primary valve seat bounding the discharge end of said extension and a valve adapted to fit said seat and having a valve stem extending therefrom, means slidably supporting said valve and valve stem along the longitudinal axis of said casing in line with said valve seat, said means including a hollow substantially cylindrical guide mounted in the wall of said extension and terminating at one end in a secondary valve seat in parallel spaced relationship to said primary valve seat, said valve abutting said secondary valve seat with its stern slidably passing therethrough into said hollow guide, means normally restraining said valve against movement toward said primary valve seat, and means responsive to liquid flow to the exclusion of gas flow, for releasing said valve and urging the same to seating position against said primary valve seat.

4. A conversion unit for converting a conventional type centrifugal pump system to a self-priming system, com prising a casing having open ends and defining a flow passage, means for introducing flow of water into said passage, said means including a priming connection extension leading into said casing through a wall thereof and having a discharge end directed substantially along the longitudinal axis of said casing, normally-open valve means adapted for closing off said extension, said normally-open valve means involving a primary valve seat bounding the discharge end of said extension and a valve adapted to fit said seat and having a valve stem extending therefrom, means slidably supporting said valve and valve stem along the longitudinal axis of said casing in line with said valve seat, said means including a hollow substantially cylindrical guide mounted in the wall of said extension and terminating at one end in a secondary valve seat in parallel spaced relationship to said primary valve seat, said valve abutting said secondary valve seat with its stem slidably passing therethrough into said hollow guide. means normally restraining said valve against movement toward said primary valve seat, said means including a flange about said stem in spaced relationship to said valve and a pair of releasable locking pawls swingably mounted in the wall of said guide and weighted for locking engagement with said flange, and means responsive to liquid How to the exclusion of gas flow, for releasing said locking pawls and urging said valve to seating position against said primary valve seat.

5. A conversion unit for converting a conventional type centrifugal pump system to a self-priming system, comprising a casing having open ends and defining a flow passage, means for introducing flow of Water into said passage, said means including a priming connection extension leading into said casing through a wall thereof and having a discharge end directed substantially along the longitudinal axis of said casing, normally-open valve means adapted for closing off said extension, said normally-open valve means involving a primary valve seat bounding the discharge end of said extension and a valve adapted to fit said seat and having a valve stem extending therefrom, means slidably supporting said valve and valve stem along the longitudinal axis of said casing in line with said valve seat, said means including a hollow substantially cylindrical guide mounted in the wall of said extension and terminating at one end in a secondary valve seat in parallel spaced relationship to said primary valve seat, said valve abutting said secondary valve seat with its stern slidably passing therethrough into said hollow guide, means normally restraining said valve against movement toward said primary valve seat, said means including a flange about said stem in spaced relationship to said valve and a pair of releasable locking pawls swingably mounted in the wall of said guide and weighted for locking engagement with said flange, and means for releasing said locking pawls and urging said valve to seating position against said primary valve seat, said means comprising a check valve assembly involving a valve seat spanning the end of said casing in proximity to said pawls and a valve engaging said seat in absence of a valve lifting force, said valve having a pawl actuating element extending therefrom in the direction of said pawls and to a point Where said pawls will be activated to unlocking position when said check valve is lifted by flow of water, but not when said check valve is lifted by flow of air.

6. A conversion unit for converting a conventional type centrifugal pump system to a self-priming system, comprising a casing having open ends and defining a flow passage, means for introducing flow of water into said passage, said means including a priming connection extension leading into said casing through a wall thereof and having a discharge end directed substantially along the longitudinal axis of said casing, normally-open valve means adapted for closing off said extension, said normally-open valve means involving a primary valve seat bounding the discharge end of said extension and a valve adapted to fit said seat and having a valve stem extending therefrom, means slidably supporting said valve and valve stem along the longitudinal axis of said casing in line with said valve seat, said means including a hollow substantially cylindrical guide mounted in the wall of said extension and terminating at one end in a secondary valve seat in parallel spaced relationship to said primary valve seat, said valve abutting said secondary valve seat with its stem slidably passing therethrough into said hollow guide, means normally restraining said valve against movement toward said primary valve seat, said means including a flange about said stem in spaced relationship to said valve and a pair of releasable locking pawls swingably mounted in the wall of said guide and weighted for locking engagement with said flange, and means for releasing said locking pawls and urging said valve to seating position against said primary valve seat, said means comprising a check valve assembly involving a valve seat spanning the end of said casing in proximity to said pawls and a valve engaging said seat in absence of a valve lifting force, said valve having a pawl actuating element extending therefrom in the direction of said pawls and to a point where said pawls will be activated to unlocking position when said check valve is lifted by flow of water, but not when said check valve is lifted by flow of air, and means for precluding leakage of water through said secondary valve seat when said valve engages said primary valve seat.

References Cited in the file of this patent *UNITED STATES PATENTS 930,847 Dolley Aug. 10, 1909 1,910,531 Ferguson May 23, 1933 2,308,727 Temple Jan. 19, 1943 2,329,495 Van Pelt Sept. 14, 1943 2,371,720 Stine Mar. 20, 1945 2,510,190 Nicolette June 6, 1950 2,512,189 Waterman June 20, 1950 

